Claims
- 1. A catalyst comprising: (a) a non-zeolitic inorganic oxide matrix, and (b) an ultrastable Y-type crystalline zeolite, said zeolite having been pretreated by contacting said zeolite with a phosphorus compound selected rom the group consisting of phosphoric acid, phosphorous acid, a salt of phosphoric acid, a salt of phosphorous acid, and mixtures thereof for a time sufficient to composite an effective amount of phosphorus with said zeolite.
- 2. The catalyst of claim 1 wherein said zeolite is contacted with steam before being contacted with said phosphorus compound.
- 3. The catalyst of claim 2 wherein said zeolite is subjected to an atmosphere comprising from about 5 mole percent to about 100 mole percent steam at a temperature ranging from about 1000.degree. to about 1600.degree. F.
- 4. The catalyst of claim 1 wherein said phosphorus compound is selected from the group consisting of an ammonium salt of phosphoric acid, an ammonium salt of phosphorous acid and mixtures thereof.
- 5. The catalyst of claim 1 wherein said phosphorus is composited with said zeolite in an amount of at least about 0.1 weight percent, based on the weight of the zeolite, calculated as elemental phosphorus.
- 6. The catalyst of claim 1 wherein said zeolite is an ultrastable Y zeolite having a unit cell size below about 24.5 Angstroms.
- 7. The catalyst of claim 1 wherein said matrix is selected from the group consisting of silica, alumina, silica-alumina, magnesia, zirconia, titania, boria, chromia and mixtures thereof.
- 8. The catalyst of claim 1 wherein said matrix comprises silica and alumina.
- 9. The catalyst of claim 1 wherein said zeolite is present in an amount ranging from about 1 to about 40 weight percent, and wherein said phosphorus is present in an amount ranging from about 0.5 to 5 weight percent based on said zeolite, and wherein said matrix comprises silica and alumina.
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part application of U.S. Ser. No. 884,522, filed July 11, 1986 now abandoned.
US Referenced Citations (6)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
884522 |
Jul 1986 |
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